BER Performance of Frequency-coded Multiple Rank Modulation

Abstract

A signal transmission technique is proposed where different ranks of frequency subcarriers are used to convey information to the receiver i.e. Frequency-coded Multiple Rank Modulation (FMRM). In FMRM, the number of the subcarriers is determined by the input stream of information bits. The input information bit stream, which is random, is sent into the ranking modulator. Instead of detecting the channel index, the receiver detects the number of frequency subcarriers of an Orthogonal Frequency Division Multiplexing (OFDM) scheme. The pattern of frequency subcarriers is pre-set and known at the receiver using the system mapper. Only the rank information is used to decode the bits in the frequency domain. Analytical upper bounds on Bit Error Probability (BEP) of the FMRM system are derived and then compared with simulation results for different transmission schemes at similar data rates, which show tractable performance. In addition to improved data rates, for better information security operations, the FMRM system has the additional benefit that the wireless channel does not completely modulate the information sent, but the information is also modulated by the number of frequency chains.